U.S. Pat. No. 5,805,529, which is incorporated by reference, describes one type of flextensional projector referred to as a Folded Shell Projector having reduced depth sensitivity and increased thermal conductance to the surrounding fluid by using a one-piece thin walled folded shell as a radiating surface.
The acoustic projector described in U.S. Pat. No. 5,805,529 has a pair of spaced apart end plates with a piezeoelectric driver positioned between the end plates, the driver having smaller cross-sectional dimensions than the end plates which have edges secured to an outer one-piece thin walled shell that provides an enclosure for the driver, the thin walled shell having a concavely inwardly bent surface between the end plates and a plurality of axially extending corrugations to provide a predetermined axial compliance and radial to axial transformation ratio.